gas gauge doesnt work but light does..

[GSXdsm97]

My gas gauge isnt moving past half a tank and my light just went on, any ideas. I recently took out my fuel pump becasue it wasnt getting any power so I ran a new line to it. Now my gauge isnt reading right any ideas

 

[1992awdlaser]

You bent the sending unit arm when putting the assembly back in the car or when taking it out.

 

[GSXdsm97]

can I just bend it back or do I now need a new one. and how do you know its bent..

 

[1992awdlaser]

Yes, you can bend it back.

2G AWD fuel pump install

Pictures 15 and 16 show the piece I am talking about. It is the metal arm with the black float on the end. When the amount of gas in your tank changes this arm moves up(more gas) or down(less gas) because of the float. It sends an electrical signal to the gas gauge to tell the gauge how far to move. The signal varies depending on the location of the arm. It does this because there is a resistor connected to it. When the arm goes up a contact point on the resistor also goes up and creates less resistance. When this happens the gauge will show full. If you bend the end with the float up towards the top of the tank then it will show empty when there is gas in the tank. It will do this because the float isn't floating on any fuel since it is bent up. So the whole arm moves down completely which causes the contact point to be at the far end of the resistor. Since it is at the far end of the resistor there is the most resistance which will show an empty tank on th gauge. Since it is bent up it will only move once there is enough fuel in the tank to make contact with the float. Yours does this when the tank is half full. That is when it will start to move the gauge. Now the arm has only half its range of motion from being bent up to the point of it not moving until the tank is half full. Since it only has half its range of motion the contact point can only move half way on the resistor which will show half a tank.

 

[GSXdsm97]

ok but why is the light comming on? does it know that there isnt any gas in there even though it is showing a half a tank

 

[kahl23]

My gauge is exactly the same, stuck at 1/2 full with a working idiot light. IIRC the the light comes on at around 2 gallons.

 

[GSXdsm97]

o ok so the sensor for my light is still working correctly just my float in the tank is bent.

 

[pimpin81]

hey at least you still got the idot light.. would have sucked to be stranded.

 

[GSXdsm97]

ha true statement indeed. but it sucks now becasue everytime I have to fill it up, with the gas prices im not trying to do that.

 

[GSXdsm97]

I filled my tank up today and the needle went to full, ill drive it around to see if it goesa past the point were it stopped before.